Patent literature 1 describes a solid state imaging device capable of performing simultaneous electronic shutter operation on all pixels. The solid state imaging device closes the 1st transfer gates all together after resetting every photodiodes to accumulate the electric charge on each of the photodiodes. After a certain shutter time has elapsed, the 1st transfer gates are opened all together to transfer the accumulated electric charge to respective charge accumulation areas. Patent literature 2 describes an active pixel sensor array which performs electronic shutter operation. Patent literature 3 describes a pixel circuit for distance image sensors, in which an oxide film is formed on a silicon substrate, and two photo gate electrodes for transferring the charge are provided on the oxide film. In an edge area of the oxide film, a floating diffusion layer is provided for taking out the charge. Patent literature 4 describes a method and device for detecting and demodulating intensity-modulated radiation field. The method and device controls an electronic switch for sensor element so as to transfer signal charge, which is generated by a photo sensitive portion of a sensor element array, to memory cell in sync with the modulated signal, which is generated by a light source, as well as controlling the memory cell so as to transfer the signal charge stored in the memory cell to an evaluation unit. Patent literature 5 describes an active pixel sensor. The active pixel sensor has: a photodetection area which generates photocharge, which is collected as signal charge, from the input light; and a transistor which transfers the signal charge from the photodetection area to a sense node connected to an input of an amplifier within the pixel. The pixel is designed so that the photodetection area has a two-dimensional symmetry with respect to a central axis thereof. Patent literature 6 describes a three-dimensional imaging system which uses TOF method. Each pixel of the three-dimensional imaging system includes a pixel detector, a charge collector and an electronic shutter; the electronic shutter is disposed between the pixel detector and the charge collector. Non patent literature 1 describes a distance measuring sensor using a CCD. Delayed time of reflected light is measured as a phase shift amount between two detection periods.